Cam lock slack adjuster

Abstract

A brake cylinder comprises a brake actuator device having a fluid operable piston and a coaxial adjoining hand brake operable device for axial actuation of a coaxial tubular push rod, there being a slack adjuster for selectively adjusting the retraction of the push rod. An actuating rod is connected to the piston and the actuating rod is selectively connected and disconnected from the internal periphery of the push rod by locking rollers selectively cooperating with a wedge shaped annulus disposed between the actuator rod and the inner periphery of the push rod. Slack adjustment is permitted by axial travel of the push rod beyond free travel limits as permitted by a friction sleeve connection between the outer periphery of the push rod and the brake cylinder housing. In a modification, the locking device is provided for a fluid spread brake cylinder that is adapted by levers to be connected to a conventional freight brake rigging to be used, for example, for hand brake applications.

What is claimed is: 
     
       1. A combined brake actuator, slack adjuster, and lock for railway vehicle brakes comprising, cylindrical brake housing means containing a fluid operable piston and coaxial adjoining hand brake operable means operable to actuate a coaxial tubular push rod for governing application of brakes of a vehicle through slack adjuster means in response to either fluid pressure in a brake cylinder chamber or actuation of the hand brake operable means, wherein improved slack adjusting means is provided for adjustably connecting the piston to the push rod comprising: (a) actuating rod means having an actuating rod, one end of which is connected to the piston and the other end of which extends within the tubular push rod for selectively axially actuating the push rod in accordance with axial actuation of the piston,   (b) annular locking means disposed within the tubular push rod secured in part to said other end of the push rod and operable to selectively operably connect the actuating rod means to the inner periphery of the push rod, and   (c) adjusting means including a friction sleeve on a portion of the outer periphery of the push rod having, restricted free axial movement within the housing for causing axial adjustment of the push rod relative to the actuating rod for automatic slack adjustment for wear in the brakes.   
     
     
       2. A combined brake actuator, slack adjuster, and lock for railway vehicle brakes according to claim 1 wherein the annular locking means comprises tubular bearing retainer means disposed coaxially within the push rod and outside of the actuator rod retaining a bearing for selectively locking the actuating rod to the push rod. 
     
     
       3. A combined brake actuator, slack adjuster, and lock for railway vehicle brakes according to claim 2 wherein the tubular bearing retainer means comprises: (a) a tubular rod having a bearing retained on one end thereof for selectively locking the actuating rod at said other end to the inner periphery of the push rod, and   (b) means for biasing the tubular rod axially against a fixed stop to unlock connection of the actuating rod to the push rod after the actuating rod has been retracted axially subsequent to brake application.   
     
     
       4. A combined brake actuator, slack adjuster, and lock for railway vehicle brakes according to claim 3 wherein the biasing means comprises a spring that is disposed on the outside periphery of the actuating rod and inside of the tubular rod and is maintained under compression between a stop on the actuating rod at one end of the spring and a stop on the tubular rod at the other end of the spring.